Chopper arrangement for an agricultural harvester

Abstract

A chopper arrangement for an agricultural harvester, having a housing and a plurality of rotatable knife rows in the housing. The chopper arrangement includes a counter knife arrangement including a first counter knife bank and a second counter knife bank downstream of the first counter knife bank. The counter knife arrangement is movable between an engaged position, in which the first and second counter knife banks at least partially overlap the plurality of rotatable knife rows, and a disengaged position, in which the first and second counter knife banks are retracted away from the plurality of rotatable knife rows. The counter knife arrangement also includes a mechanical linkage coupling the first counter knife bank to the second counter knife bank to provide for simultaneous movement of the first and second counter knife banks upon actuation of the counter knife arrangement between the engaged and disengaged positions.

What is claimed is: 
     
       1. A chopper arrangement for an agricultural harvester, the chopper arrangement comprising:
 a housing; 
 a plurality of rotatable knife rows in the housing, the plurality of rotatable knife rows rotatable about a knife row axis to move crop material in the housing along a crop flow path; and 
 a counter knife arrangement movable between an engaged position and a disengage position, the counter knife arrangement comprising:
 a first counter knife bank rotatable about a first counter knife bank axis, the first counter knife bank axis positioned vertically above the first counter knife bank and the knife row axis; 
 a second counter knife bank rotatable about a second counter knife bank axis and downstream of the first counter knife bank according to the crop flow path, the second counter knife bank axis positioned below the knife row axis; 
 a mechanical linkage coupling the first counter knife bank to the second counter knife bank to provide for simultaneous movement of the first counter knife bank and the second counter knife bank upon actuation of the counter knife arrangement between the engaged position and the disengaged position, 
 
 wherein in the engaged position the first counter knife bank and the second counter knife bank at least partially overlap the plurality of rotatable knife rows, and 
 wherein in the disengaged position the first counter knife bank and the second counter knife bank are retracted away from the plurality of rotatable knife rows. 
 
     
     
       2. The chopper arrangement according to  claim 1 , wherein the mechanical linkage comprises:
 a first bracket fixedly attached to the first counter knife bank and pivotably attached to the housing, and 
 a second bracket fixedly attached to the second counter knife bank and pivotably attached to the housing, 
 wherein the first bracket and the second bracket are arranged to pivot relative to the housing upon actuation of the counter knife arrangement between the engaged position and the disengaged position. 
 
     
     
       3. The chopper arrangement according to  claim 2 , wherein the mechanical linkage further comprises an elongate connector having a first connector end and a second connector end opposite the first connector end, the elongate connector being pivotably attached to the first bracket at the first connector end and being pivotably attached to the second bracket at the second connector end to provide for relative rotational movement between the first bracket and the second bracket upon actuation of the counter knife arrangement between the engaged position and the disengaged position. 
     
     
       4. The chopper arrangement according to  claim 2 , wherein the chopper arrangement comprises an actuating arm pivotably attached to the housing, the actuating arm and the first bracket being pivotably attached to the housing at a common pivot point, wherein actuation of the actuating arm about the common pivot point causes actuation of the first bracket about the common pivot point to move the counter knife arrangement between the engaged position and the disengaged position. 
     
     
       5. The chopper arrangement according to  claim 4 , wherein the actuating arm includes a first actuating arm at a first side of the first counter knife bank and the second counter knife bank and a second actuating arm at a second side of the first counter knife and the second counter knife bank opposite the first side. 
     
     
       6. The chopper arrangement according to  claim 4 , wherein an operator rotates the actuating arm. 
     
     
       7. The chopper arrangement according to  claim 1 , wherein, in the engaged position of the counter knife arrangement, a degree of overlap between the first counter knife bank and the plurality of rotatable knife rows is greater than a degree of overlap between the second counter knife bank and the plurality of rotatable knife rows. 
     
     
       8. The chopper arrangement according to  claim 1 , wherein in a first range of positions of the counter knife arrangement between a first intermediate position and a second intermediate position of the counter knife arrangement, the first intermediate position and the second intermediate position being between the engaged position and the disengaged position, the first counter knife bank partially overlaps the plurality of rotatable knife rows and the second counter knife bank does not overlap the plurality of rotatable knife rows. 
     
     
       9. The chopper arrangement according to  claim 8 , wherein in a second range of positions of the counter knife arrangement between the second intermediate position and the engaged position of the counter knife arrangement, the second intermediate position being between the first intermediate position and the engaged position, the second counter knife bank at least partially overlaps the plurality of rotatable knife rows. 
     
     
       10. The chopper arrangement according to  claim 8 , wherein in the second intermediate position a degree of overlap between the first counter knife bank and the plurality of rotatable knife rows is less than 50%. 
     
     
       11. The chopper arrangement according to  claim 1 , wherein an angle of overlap between the first counter knife bank and the plurality of rotatable knife rows is different for different positions of the counter knife arrangement. 
     
     
       12. The chopper arrangement according to  claim 11 , wherein the angle of overlap between the first counter knife bank and the plurality of rotatable knife rows is smallest when the counter knife arrangement is in the engaged position. 
     
     
       13. The chopper arrangement according to  claim 11 , wherein the angle of overlap between the first counter knife bank and the plurality of rotatable knife rows is different from an angle of overlap between the second counter knife bank and the plurality of rotatable knife rows in a given position of the counter knife arrangement. 
     
     
       14. A method of operating a chopper arrangement for an agricultural harvester, the chopper arrangement comprising a counter knife arrangement having a first counter knife bank and a second counter knife bank that are mechanically coupled together, the counter knife arrangement being movable between an engaged position, in which the first counter knife bank and the second counter knife bank at least partially overlap a plurality of rotatable knife rows of the chopper arrangement, and a disengaged position, in which the first counter knife bank and the second counter knife bank are retracted away from the plurality of rotatable knife rows, the method comprising:
 actuating the counter knife arrangement to a position between the engaged position and the disengaged position to control an intensity of chopping performed on crop material processed by the agricultural harvester, wherein actuation of the counter knife arrangement causes simultaneous movement of the first counter knife bank and the second counter knife bank between the engaged position and the disengaged position by rotating the first knife bank about a first counter knife bank axis positioned above the first counter knife bank and the second knife bank about a second counter knife bank axis positioned above the second counter knife bank. 
 
     
     
       15. A chopper arrangement for an agricultural harvester, the chopper arrangement comprising:
 a housing; 
 a plurality of rotatable knife rows in the housing, the plurality of rotatable knife rows rotatable about an axis to move crop material in the housing along a crop flow path; and 
 a counter knife arrangement movable between an engaged position and a disengage position, the counter knife arrangement comprising:
 a first counter knife bank; 
 a second counter knife bank downstream of the first counter knife bank according to the crop flow path; 
 a first bracket having a first end portion pivotably attached to the housing, wherein the first counter knife bank is operably coupled with the first bracket at an intermediate portion of the first bracket; 
 a second bracket fixedly attached to the second counter knife bank on a first end portion and pivotably attached to the housing at an intermediate portion of the second bracket; and 
 a mechanical linkage coupled to the first bracket at a second end portion on an opposing side of the first counter knife bank and to the second bracket at a second end portion on an opposing side of the second bracket pivot point from the second counter knife bank, the mechanical linkage configured to provide for simultaneous movement of the first counter knife bank and the second counter knife bank upon actuation of the counter knife arrangement between the engaged position and the disengaged position.